Biliary tract cancer is a rare gastrointestinal malignant neoplasm and includes intrahepatic cholangiocarcinoma, extrahepatic cholangiocarcinoma, and gall bladder cancer. Curative surgical resection offers the only chance for cure. However, most patients with BTC are diagnosed at an unresectable stage. Therefore, the survival outcomes of patients with advanced biliary tract cancer remain dismal.

The combination of gemcitabine and cisplatin has become the current standard for advanced BTCs since the landmark ABC-02 trial in 2010. However, the median overall survival of Gem/Cis chemotherapy is less than 1 year. Recently, a triplet regimen of gemcitabine, cisplatin, and nab-paclitaxel showed promising results in a single-arm phase II multicenter study.

However, biliary tract cancer is a group of heterogenous diseases by site and genetic alteration, and this diversity may lead differences in response to systemic chemotherapy.

Transcriptome analysis through RNA-sequencing has rarely been performed in advanced biliary tract cancer, and even if it has performed, only small number of patients were included. Further research on multi-omics data is needed on the necessity and clinical significance in treatment of biliary tract cancer.

Using biopsy specimen (formalin fixed paraffin embedded tissue), in-house NGS and RNA-sequencing will be performed simultaneously. Through this, investigators will discover biomarkers based on multi-omics data that predict response to systemic chemotherapy (nab-paclitaxel plus gemcitabine-cisplatin). In addition, blood sampling will be performed in parallel to conduct research on cell-free DNA and circulating tumor cell analysis related to response and progression on chemotherapy; before administration of chemotherapy, 3 months after chemotherapy, 6 months after chemotherapy, the time of disease progression (if possible), before curative resection (if possible).

Inclusion Criteria:

• Age ≥ 19 years old
• Capable of understanding and complying with the protocol requirements and signed informed consent
• The patients were confirmed as bilary tract cancer (gall bladder cancer, extrahepatic cholangiocarcinoma, intrahepatic cholangiocarcinoma) by histopathology or cytology
• Patients with inoperable or metastatic or recurrent biliary tract cancer
• Patients who underwent in-house next-generation sequencing
• Patients planning to receive Gemcitabine, Cisplatin, nab-paclitaxel triplet chemotherapy
• At least one measurable objective lesion was identified based on the RECIST 1.1 criteria
• Eastern Cooperative Oncology Group (ECOG) performance status of 0-1.
• The expected survival a ≥3 months

Exclusion Criteria:

• The subject has uncontrolled, significant intercurrent or recent illness including infection for organ failure
• Prior palliative chemotherapy for biliary tract cancer
• Dementia, altered mental state, or any mental illness that prevents understanding or informed consent
• Other conditions that researchers not think to be suitable for enrollment.

Patients with advanced biliary tract cancer will be recruited at CHA Bundang Medical Center